# [IPk] Changing basals

```Hi Pat
I too use the temp. basal rate a lot.
Usually it's either an increase to simulate a square wave bolus (I have an
MM 506 which doesn't have that feature) or a temp. increase to cover
exercise.

For the square wave, it's fairly easy to figure out.
My normal daytime basal is 1.0 units/hour.
Say I have 40g carbs, I might want to take half as a bolus and the rest
over the next 2 hours. So, I have 20g carbs over 2 hours. I take i unit per
15g carbs. So, 20g carbs is a total of 1.3 units. Divide that by 2 (to get
the additional basal per hour) and you get an increase of 0.65 units per
hour (which I would round up or down to 0.6 or 0.7). So, I set my temp
basal rate to 1 + 0.7 = 1.7, for a duration of 2 hours.
That sounds quite complicated, but when you do it, it's quite easy.

I think it would be much harder to hassle with percentages, and with the
DIsetronic, you can't set the duration of the basal change, which is really
annoying.

Of course, sometimes the maths is a little tricky, but I'm lucky inthat I'm
very good at mental arithmetic. I've never needed a calculator for insulin
doses yet!

Reducing the basal is much easier.
Say I'm going to dance for 3 hours. About 30 mins. before, I set the temp.
basal rate for a 50% reduction (I guess here it's as easy with the
Disetronic). But half of 1.0 isn't exactly hard to calculate!  So I set the
temp basal for 3 hours at a rate of 0.5 units/hour (so that the temp rate
finishes half an hour before I finish dancing). If I then need to alter it,
say because I end up dancing for an extra hour, I just reset the temp rate.

For changing basals over a period of days, that's where the multiple
profiles on the 508 comes in.
Since I don't have that, I just reset the normal basal. It starts from
midnight, so you go through each "time zone" and change it accordingly. The
only problem is to remember what it was before, if you're going to need to
change it back again later.
I try and remember to write it down, especially when I'm trying different
things to see what works.

I'm still trying to get the basal right for certain weeks in the month.
I "think" I now need to decrease by 0.1 units across the board a week
before my period, and then increase by 0.1 units (above my normal rate) for
the following week, and then back to normal for the next 2 weeks. I'm not
convinced about that increase, but it's looking likely. The fact that my
cycles are completely and utterly irregular doesn't make it easy though!

If you want to change basals a lot, I think the MM definitely has some